. cxiv. 309 



3. LITHOLEPIS, Rafinesque. ALLIGATOR GABS. 



= AtractosteuS) Raf. 



1. L. acfamantinus, Raf. GEE AT GAB. ALLIGATOB GAB. 

 DIAMOND FISH. Snout broad, depressed, the length of 

 the cleft of the mouth being about half the length of the 

 head; color olivaceous; very large, reaching a length of 

 of 8 feet or more. Mississippi Valley, N. to Illinois and 

 Ohio, abundant southward. (A. ferox, Raf., but the 

 name here adopted has precedence. Perhaps some still 

 older specific name may be found.) 



OEDEE EE.-SELACHOSTOMI. 



(The Spoon-Bias.) 

 This order contains but the single family Potyodontidce. 



FAMILY CXIV.--POLYODONTID^E. 



(The Spoon-Billed Cats.) 



Body elongated; skin naked, with minute stellated 

 roughnesses, and some bony plates about head and tail; 

 mouth very wide, not inferior but overhung by the long 

 snout; minute teeth on lower jaw, maxillaries and palate, 

 teeth sometimes deciduous with age ; snout produced into 

 a very long and spatula-like process, thin and flexible at 

 its edges; no barbels; caudal with fulcra, as in Lepidos- 

 teus, heterocercal, the lower lobe well developed; opercle 

 with a long flap reaching to pectorals, or beyond and 

 sometimes to ventrals; spiracles present; no tongue; one 

 broad -branchiostegal; air bladder large, communicating 

 with the oesophagus; intestine with a well developed 

 spiral valve; stomach coecal, with a broad divided pyloric 



